1·Nuclear radiation cannot be seen, smelled, or otherwise detected by normal senses.
核辐射看不见，闻不到，也不能通过我们正常的感官能够觉察到。
2·Nuclear radiation, invisible and insidious, gives us the creeps.
核辐射的无形性和潜伏性令人类闻风丧胆。
3·So why is nuclear radiation so fearsome, and what determines how we react when faced with a threat, imagined or real?
那么，为何核辐射如此可怕，是什么决定我们面对危险(真实的或想象的)时如何反应？
4·If the burst is shallow enough to penetrate the surface, blast, thermal, and initial nuclear radiation effects will be present, but will be less than for a surface burst of comparable yield.
如果离地面够浅以致能穿透表面，那么将出现冲击波、热辐射以及早期核辐射作用，但是作用效果要小于近似当量的地面爆炸。
5·This fallout material decays over a long period of time, and is the main source of residual nuclear radiation.
尘降物需要很长的时间才会衰减，这是核辐射残留的主要来源。